Bidirectional cavopulmonary anastomosis with additional pulmonary blood flow: good or bad pre-Fontan strategy

Objectives

This study aimed to evaluate the influence of preserved additional pulmonary blood flow (APBF) on survival after bidirectional cavopulmonary shunt (BCPS) and completion of Fontan circulation.

Methods

From March 2003 and April 2015, 156 patients with a single ventricle underwent BCPS. After performing propensity score analysis (1:1) for the entire sample, 50 patients with APBF (APBF group) were matched with 50 patients without APBF (no-APBF group).

Results

Age ( P  = 0.90), sex ( P  = 0.57), weight ( P  = 0.75), single ventricle morphology ( P =  0.87), type of neonatal palliative procedure ( P =  0.52), saturation ( P =  0.35), ejection fraction ( P =  0.90), Nakata index ( P  = 0.70) and mean pulmonary artery pressure ( P  = 0.72) were not significantly different between the groups. No significant survival difference was demonstrated ( P  = 0.54). One and 4-year survival rates were both 89.1% ± 4.6% in the APBF group and 87.2% ± 4.9% and 83.4% ± 5.9%, respectively, in the no-APBF group. There was no significant difference in rates of Fontan completion ( P  = 0.24), which was achieved in 22 patients from the APBF group (55.0%) and 26 patients from the no-APBF group (65.0%). However, Fontan completion occurred significantly earlier in the no-APBF group ( P  < 0.01). In this group, Fontan procedure was performed before 36 months of inter-stage period in 45.9% ± 8.5% of cases (95% CI 31.0-63.7%) compared to only 13.3 ± 5.6% (95% CI 5.8-29.1%) in the APBF group.

Conclusions

Our study demonstrates that APBF does not affect survival after BCPS or Fontan completion rate. APBF allows postponing the Fontan procedure without a negative effect on clinical status.

Arrhythmias After Fontan Operation with Intra-atrial Lateral Tunnel Versus Extra-cardiac Conduit: A Systematic Review and Meta-analysis

Current studies on the incidence of arrhythmias after the intra-atrial lateral tunnel (ILT) Fontan operation and the extra-cardiac conduit (ECC) Fontan operation are limited, with controversial results. This systematic review aimed to compare the prevalence of arrhythmias in patients who underwent ECC or ILT Fontan. Relevant studies comparing the incidence of arrhythmias and pacemaker implantation in ILT with ECC were identified through a literature search using MEDLINE, EMBASE, and the cochrane central register of controlled trials. The outcome measures included baseline characteristics, early (≤30 days) and late (>30 days) arrhythmias and pacemaker implantation. 16 publications involving 3499 patients were included. In the meta-analysis, although the overall risk of early arrhythmias was lower for the ILT group, statistically, no significant difference was observed (odds ratio [OR] 0.78; 95% confidence interval [CI] 0.61-1.01; p = 0.06). Similarly, there was no significant difference between the two cohorts in the incidence of postoperative permanent pacemaker therapy (OR 1.36; 95% CI 0.86-2.14; p = 0.19). However, we found significantly increased incidence of late arrhythmias in ILT group compared with ECC group (OR 1.96; 95% CI 1.64-2.35; p < 0.01). Although our systematic review and meta-analysis suggested that there was no significant difference in early arrhythmias and in pacemaker implantation between the ILT and ECC groups, ECC procedure could significantly lower the risk of late arrhythmias after Fontan surgery. Given that some limitations cannot be overcome, well-designed randomized controlled trials are needed to confirm our findings.

Non-invasive measurement of cardiac output using AESCULON® mini after Fontan operation

BACKGROUND

Electrical velocimetry correlates well with established methods of measuring cardiac output (CO) such as thermodilution and echocardiography. In this study, we compared the cardiac function of children with single right ventricle (SRV) and single left ventricle (SLV) on non-invasive postoperative measurement of hemodynamic parameters using AESCULON^® mini.

METHODS

Demographic, preoperative, and perioperative data were obtained from medical records. We retrospectively reviewed the AESCULON mini data of 21 patients with single ventricle who underwent Fontan operation. The patients were divided into two groups according to morphologic diagnosis: SRV (n = 9) and SLV (n = 12). The following hemodynamic parameters were analyzed: stroke volume (SV); CO; cardiac index (CI); stroke volume variation (SVV); and ventricular ejection time (VET).

RESULTS

Hemodynamic parameters were as follows (SRV vs SLV): heart rate (HR), 140.5 beats/min versus 121 beats/min; SV, 14.5 mL vs 19.9 mL; CO, 2 L/min vs 2.3 L/min; CI, 4.3 L/min/m² versus 4.4 L/min/m² ; SVV, 15.5% versus 13.9%; and VET, 167.7 s versus 197.7 s. HR and VET were statistically different between the two groups.

CONCLUSIONS

CI does not differ with laterality of the single ventricle. SRV VET, however, was significantly shorter than SLV VET in the acute postoperative period. Conversely, SRV HR was higher than SLV HR, which may mean that SRV compensates for lower VET by increasing HR.

Quantification of ventricular unloading by 3D echocardiography in single ventricle of left ventricular morphology following superior cavo-pulmonary anastomosis and Fontan completion - a feasibility study

BACKGROUND

Three-dimensional echocardiography. (3DE) is comparable to cardiac magnetic resonance imaging for estimating ventricular volume in congenital heart diseases. However, there are limited data on estimation of ventricular volumes by 3DE in univentricular heart and change in ventricular volumes after surgical creation of cavopulmonary connection. We sought to quantify the unloading of the single ventricle of left ventricular. (LV) morphology by 3DE after superior cavopulmonary anastomosis. (SCPA) or Fontan operation over a period of 3 months and thereby derive a preliminary 3DE data set on this patient subset.

PATIENTS AND METHODS

Eighteen patients with functional single ventricle of LV morphology, who underwent SCPA or completion of Fontan circulation, were included in the study. Volume of the ventricle was estimated by 3DE before surgery and after surgery. (in the early postoperative phase and 3 months after surgery), and indexed end-diastolic volume. (EDV), end-systolic volume. (ESV), and ejection fraction. (EF) were derived.

RESULTS

Twelve patients underwent SCPA and six patients underwent staged completion of Fontan circulation. Before surgery, EDV was similar in both groups. There was a significant fall in EDV immediately after SCPA (from 48.3 ± 14.9 ml/m² to 39.5 ± 12.3 ml/m²). However, EDV increased at 3 months' follow-up to 41.3 ± 10.5 ml/m². There was no significant fall in EDV immediately after Fontan operation (47.2 ± 10.1 ml/m²-46.6 ± 14.2 ml/m²), but EDV continued to fall at 3 months of follow-up (44.7 ± 10. ml/m²). There was no significant change in ESV in either group, but EF fell significantly after SCPA.

CONCLUSIONS

We provide preliminary information on 3DE volume data of single ventricle of LV morphology and the pattern of unloading after SCPA and Fontan operation. Immediate significant volume unloading occurred after SCPA which tended to catch-up after 3 months, whereas continued fall in ventricular volume with time was noted after Fontan.

Sudden cardiac arrest in patients following surgery for CHD

The prevalence of sudden cardiac arrest after surgery for CHD is primarily related to the complexity of the congenital defect and the presence of residual defects, especially ventricular dysfunction. Among all causes of death in patients having CHD, about 19% lead to sudden mortality. The specific risk factors associated with the various congenital defects are poorly understood. The lone exception is tetralogy of Fallot, largely due to its high prevalence and the historically high post-operative survival rate. In tetralogy of Fallot, historical, haemodynamic, and electrical features contribute to risk, and electrophysiologic testing may be helpful, particularly to rule out risk. An implantable cardioverter-defibrillator is highly effective for secondary prevention in most forms of CHD, and future advances will improve its role in primary prevention.

Results of the Fontan operation with no early mortality in 248 consecutive patients

BACKGROUND

The Fontan operation has undergone several modifications and today is the primary way to treat a broad spectrum of congenital heart defects.

AIM

The purpose of this study is to present the results of treatment of children with a single ventricle operated by the same surgical team and managed according to a uniform strategy.

METHODS

In the years 2007-2015, in 248 children aged 3.7 ± 2.6 years and weighing 14.6 ± 6.1 kg with a single ventricle, Fontan surgery was performed. In 56 (22.6%) children surgery was based on the creation of an intra-atrial lateral tunnel, and in 192 (77.4%) patients extracardiac modification was performed. In most patients, the operation was carried out with the normothermic cardiopulmonary bypass, on a "beating heart" without aortic cross-clamp. The average cardiopulmonary bypass time was 53.9 ± 23.9 min. The most common indication for surgery was hypoplastic left heart syndrome (53.6%). All patients with a single ventricle referred to our hospital for the Fontan procedure were enrolled into the surgery programme.

RESULTS

All patients survived the operation and were discharged home. Thirty-six (14.5%) patients were extubated in the operating room, in other patients the mean duration of the mechanical ventilation was 9.7 ± 16.1 h (median 7 h). The average time of hospitalisation in the whole study group was 17.5 ± 18.5 days (median 15 days). After surgery, in four children transient seizures occurred, and three patients had an ischaemic stroke.

CONCLUSIONS

Developing and obeying a fixed perioperative protocol is crucial for low mortality and small number of complications after Fontan operation.

An Observation from Liver Biopsies Two Decades Post-Fontan

This brief report describes an observation from liver biopsy results in nonfailing Fontan patients, currently in their second postoperative decade. In three patients, with either atriopulmonary or atrioventricular connections and functional left ventricles, we found no portal fibrosis. In contrast, we found portal fibrosis in three clinically similar, nonfailing Fontan patients with lateral tunnel connections and functional left ventricles. We recognize the results may be secondary to chance; nevertheless, we speculate about possible relevancy.

[Antibradycardia therapy : Indication and implementation]

Pacemaker therapy (PMT) in grown-up congenital heart disease (GUCH) must meet the demands of a young, dynamic and heterogeneous group of patients. The duration of the therapy has to be planned for several decades and should be accompanied by an invasive procedure at the very least. Most of the patients enter adulthood with their pacemaker (PM) already implanted; for others the indications can be derived from the published guidelines for GUCH and PMT, but need to be adjusted to the individual situation of the patient. Depending on the underlying heart disease the decision on the use of either an epimyocardial or a transvenous PM system has to be made. Both electrodes and PM should correspond to the latest technical developments to optimally adapt to the patients' multiple requirements. In the case of PM system revisions abandoned leads should be removed and vascular stenosis or occlusions cleared to be prepared for later revisions. During any cardiac surgery epimyocardial PM systems should be checked against the patient's needs and expanded or revised accordingly. Epimyocardial resynchronization systems in particular offer more opportunities for compensating for cardiac dysfunction with greater reliability using a second ventricular lead. The PMT is an essential part of the medical treatment for many patients with GUCH and contributes significantly to the well-being and quality of life. Against this background, a competent and consequent follow-up regime requires experienced physicians. An integrated telemetric monitoring system for the PM has proven valuable and supports the early recognition of cardiac arrhythmia.

Adult patients with Fontan circulation: What we know and how to manage adults with Fontan circulation?

Most of patients after the Fontan operation can reach their adulthood, however, the management strategy for this complex pathophysiology has not been yet established. In general, elevated central venous pressure (CVP) and low cardiac output (CO) due to impaired ventricular preload characterize the Fontan circulation and the ideal hemodynamics could be a combination of a lower CVP with a higher CO. Thus, preserved functional systemic ventricle with low pulmonary artery resistance is thought to be crucial for better long-term outcome. However, on the other hand, because of the unique hemodynamics, these patients have significantly higher incidence of complications, sequelae, and even mortality. The major complications are supraventricular arrhythmias, heart failure, and Fontan-related problems, including protein-losing enteropathy and pulmonary arteriovenous fistulae, both of which are refractory to the treatments, and most of these "Fontan inconveniences" increase as patients age. In addition, one of the recent emerging problems is Fontan-associated liver disease that includes liver cirrhosis and hepatocellular carcinoma. Furthermore, women with Fontan circulation also reach childbearing age and there have been increasing numbers of reports showing a high incidence of pregnancy-associated complications. All these problems may be a part of "Fontan inconveniences" because most of the current Fontan patients are still "young" i.e. in their twenties or thirties and it may be not surprising that more new Fontan-associated pathophysiology emerges as patients age. Recent evidence reminds us of the concept that adult Fontan pathophysiology is not just a cardiovascular disease, rather, a multiorgan disease with many interactions between cardiovascular and non-cardiovascular organs. Therefore, a multidisciplinary approach is mandatory to take care of and anticipate the better long-term outcome.

TGF-β receptor 1 inhibition prevents stenosis of tissue-engineered vascular grafts by reducing host mononuclear phagocyte activation

Stenosis is a critical problem in the long-term efficacy of tissue-engineered vascular grafts (TEVGs). We previously showed that host monocyte infiltration and activation within the graft drives stenosis and that TGF-β receptor 1 (TGF-βR1) inhibition can prevent it, but the latter effect was attributed primarily to inhibition of mesenchymal cell expansion. In this study, we assessed the effects of TGF-βR1 inhibition on the host monocytes. Biodegradable TEVGs were implanted as inferior vena cava interposition conduits in 2 groups of C57BL/6 mice (n = 25/group): unseeded grafts and unseeded grafts with TGF-βR1 inhibitor systemic treatment for the first 2 wk. The TGF-βR1 inhibitor treatment effectively improved TEVG patency at 6 mo compared to the untreated control group (91.7 vs. 48%, P < 0.001), which is associated with a reduction in classic activation of mononuclear phagocytes. Consistent with these findings, the addition of rTGF-β to LPS/IFN-γ-stimulated monocytes enhanced secretion of inflammatory cytokines TNF-α, IL-12, and IL-6; this effect was blocked by TGF-βR1 inhibition (P < 0.0001). These findings suggest that the TGF-β signaling pathway contributes to TEVG stenosis by inducing classic activation of host monocytes. Furthermore, blocking monocyte activation by TGF-βR1 inhibition provides a viable strategy for preventing TEVG stenosis while maintaining neotissue formation.-Lee, Y.-U., de Dios Ruiz-Rosado, J., Mahler, N., Best, C. A., Tara, S., Yi, T., Shoji, T., Sugiura, T., Lee, A. Y., Robledo-Avila, F., Hibino, N., Pober, J. S., Shinoka, T., Partida-Sanchez, S., Breuer, C. K. TGF-β receptor 1 inhibition prevents stenosis of tissue-engineered vascular grafts by reducing host mononuclear phagocyte activation.

Outcomes of Fontan conversion for failing Fontan circulation: mid-term results

OBJECTIVES

We investigated the results of a revision of a previous Fontan connection to total cavopulmonary connection (TCPC) in patients with failing Fontan circulation.

METHODS

From July 1998 to April 2013, 21 patients who had failing Fontan circulation underwent revision of the previous Fontan operation to TCPC. The median age at TCPC conversion was 17.9 years (range, 4.6-38.1 years) and the median interval between initial Fontan operation and TCPC was 13.8 years (range, 2.1-25.4 years). There were 37 indications for Fontan revision in 21 patients. The indications were huge right atrium (n = 15), atrial arrhythmia (n = 8), intra-atrial thrombi (n = 6), protein-losing enteropathy (PLE) (n = 3) and more than mild atrioventricular valve regurgitation (n = 5). The previous Fontan operation was revised to extracardiac conduit replacement (n = 20) and intra-atrial lateral tunnel (n = 1). Concomitant surgery for atrial arrhythmia was performed in 8 patients. Fenestration was performed in 7 patients. The median follow-up duration was 7.1 years (range, 0.3-13.4 years).

RESULTS

There were no operative deaths and two late deaths occurred 7.9 and 8.1 years after operation. Actuarial 5- and 10-year survival rates were 92.3 and 83.1%, respectively. Postoperative complications included bleeding (n = 3), deep sternal infection (n = 1) and prolonged pleural effusion for more than 2 weeks (n = 5). During follow-up, atrial arrhythmia recurred in 6 patients, PLE recurred in 2 patients and pleural effusion recurred in 2 patients. All patients were classified as New York Heart Association Class I (n = 15) or Class II (n = 4).

CONCLUSIONS

Fontan conversion to TCPC in patients with failing Fontan circulation can be performed with low risk of morbidity and mortality. The procedure confers better quality of life and is functional for patients with failed Fontan circulation.

Rational design of an improved tissue-engineered vascular graft: determining the optimal cell dose and incubation time

AIM

We investigated the effect of cell seeding dose and incubation time on tissue-engineered vascular graft (TEVG) patency.

MATERIALS & METHODS

Various doses of bone marrow-derived mononuclear cells (BM-MNCs) were seeded onto TEVGs, incubated for 0 or 12 h, and implanted in C57BL/6 mice. Different doses of human BM-MNCs were seeded onto TEVGs and measured for cell attachment.

RESULTS

The incubation time showed no significant effect on TEVG patency. However, TEVG patency was significantly increased in a dose-dependent manner. In the human graft, more bone marrow used for seeding resulted in increased cell attachment in a dose-dependent manner.

CONCLUSION

Increasing the BM-MNC dose and reducing incubation time is a viable strategy for improving the performance and utility of the graft.

Fontan Operation: Indications, Short and Long Term Outcomes

Fontan operation, since its original description, has undergone a number of modifications so that it is now a staged, total cavo-pulmonary connection with fenestration. Stage I is palliation, depending upon the pathophysiology of the defect complex in early life, Stage II is bidirectional Glenn at about the age of 6 mo and Stage III is transfer of inferior vena caval blood to the pulmonary circuit along with fenestration between 2 to 4 y. Any patient that has only one functioning ventricle is a candidate for Fontan surgery. The morbidity and mortality have remarkably improved since the institution of staged, total cavo-pulmonary connection with fenestration. Complications during follow up continue to occur, though diminished with the newer modifications, and should be promptly addressed.

Two problems and a single solution: Covered stent implantation to close an anterograde pulmonary flow and treat hypoplastic left pulmonary artery after Fontan operation

Several issues may impact on the function of a Fontan circulation including accessory source of pulmonary blood flow and pulmonary artery anatomy. Here we report on a 5.5-year-old boy who showed failing Fontan circulation due to left pulmonary artery stenosis/hypoplasia and significant forward pulmonary blood flow through the native pulmonary artery. Successful implantation of a 34-mm CP covered stent in the left pulmonary artery in a Fontan patient was useful for simultaneous successful treatment of residual antegrade flow from the systemic ventricle to the pulmonary artery and enlargement of hypoplastic left pulmonary artery. © 2015 Wiley Periodicals, Inc.

Transarterial embolization for pediatric hepatocellular carcinoma with cardiac cirrhosis

We describe the case of a 15-year-old boy with a history of Fontan operation and multiple intrahepatic tumors. Computed tomography showed multiple hepatic nodules with arterial enhancement. Because hepatocellular carcinoma (HCC) was not detected on biopsies and tumor markers were normal, progress was monitored on imaging. One hepatic tumor increased greatly in size during follow up. At 15 years of age, tumor markers rose rapidly, and he had upper abdominal swelling. Therefore, transarterial embolization (TAE) was performed for the largest tumor, suspected to be a HCC due to cardiac cirrhosis. This tumor had not increased at follow up 4 months later. The patient died from hepatic failure at the age of 17 years, and HCC was diagnosed at autopsy. Although pediatric HCC is rare, its incidence is likely to increase. TAE, with or without anticancer agents, is a therapeutic option for unresectable pediatric HCC, as it is for adult HCC.

17-year experience in surgical management of congenitally corrected transposition of the great arteries: a single-centre's experience

OBJECTIVES

We report our surgical experience in congenitally corrected transposition of great arteries (CCTGAs) and the long-term follow-up result.

METHODS

From January 1995 to February 2012, 56 patients with CCTGA received definite surgical repair; 15 patients received conventional repair (Group I), 18 patients received anatomical repair (Group II) and 23 patients received single ventricular palliation (Group III). They were followed for early and late mortality, long-term survival, postoperative morbidity and reintervention or reoperation.

RESULTS

The overall survival rate was 80% at 16 years in Group I, 53% at 13 years in Group II and 100% at 13 years in Group III. After excluding the early surgical mortality, the long-term survival rate was 92% at 16 years in Group I, 64% at 13 years in Group II and 100% at 13 years in Group III. Patients with significant tricuspid valve regurgitation showed the worst outcome after surgery.

CONCLUSIONS

Our series showed good results with single ventricular palliation (SVP) in CCTGA with complex anatomy, but the long-term result should be followed. Anatomical repair is the choice of operation only for those with favourable anatomy. The more complicated intracardiac repair may result in late left ventricular outflow tract obstruction, various degrees of atrioventricular block, systemic or pulmonary venous return obstruction and the lack of an ideal conduit (e.g. homograft) for Rastelli reconstruction. Therefore, we preferred SVP in patients with complex and unfavourable anatomy.

Perventricular closure of pulmonary stump in a 16-kg child

Blind pouch formation of the pulmonary artery (PA) in patients having undergone a Fontan operation can present a serious risk for thromboembolic events. Either primary or secondary closure of this stump is necessary to reduce this risk. Unfortunately, secondary closure is oftentimes difficult due to the size and anatomy of the presenting patient. We describe the insertion of a muscular ventricular septal defect (VSD) device via a perventricular approach for successful closure of a pulmonary stump in a 3-year old, 16-kg child. To our knowledge, this is the first report of a perventricular approach for successful closure of a PA stump.

Pediatric split liver transplantation after Fontan procedure in left isomerism combined with biliary atresia: a case report

LI is a subset of the heterotaxy syndrome and a rare birth defect that involves the heart and other organs. It can be combined with extracardiac abnormalities, especially BA. CHD can be associated with LI in up to 15% of cases, although it is rare in BA. Pediatric LT for a child with ESLD due to BA combined with LI and CHD is a challenging issue for a transplant surgeon. Herein, we report a successful split LT on a three-yr-old boy with LI who survived after a Fontan procedure due to single ventricle, but who suffered from HPS associated with BA.

Inhaled iloprost for the treatment of patient with Fontan circulation

Decreased exercise capacity after Fontan surgery is relatively common and the failure of the Fontan state gradually increases with age. However, there is no further treatment for patients with Fontan circulation. Pulmonary vasodilation therapy is an effective method to solve this problem because pulmonary vascular resistance is a major factor of the Fontan problem. Inhaled iloprost is a chemically stable prostacyclin analogue and a potent pulmonary vasodilator. We experienced two cases of Fontan patients treated with inhaled iloprost for 12 weeks. The first patient was an 18-year-old female with pulmonary atresia with an intact ventricular septum, and the second patient was a 22-year-old male with a double outlet right ventricle. Fifteen years have passed since both patients received Fontan surgery. While the pulmonary pressure was not decreased significantly, improved exercise capacity and cardiac output were observed without any major side effects in both patients. The iloprost inhalation therapy was well tolerated and effective for the symptomatic treatment of Fontan patients.

A complete extracorporeal circulation-free approach to patients with functionally univentricular hearts provides superior early outcomes

OBJECTIVE

We compared the early outcomes of patients undergoing extracardiac total cavopulmonary connection (TCPC) with or without cardiopulmonary bypass (CPB).

METHODS

Between February 2012 and February 2013, 27 patients undergoing TCPC without CPB (off-pump group) were compared with matched 27 patients undergoing TCPC on CPB (on-pump group). Outcome parameters studied were inotropic score, time to extubation, intensive care unit (ICU) stay, first 12 hours mediastinal drainage in ICU, average pleural drainage, time to removal of chest tubes, total hospital stay, and saturation at discharge.

RESULTS

There was one early death in each group. No patient required conversion from off CPB to CPB. The inotropic score (6.1 ± 5.91 vs 10.1 ± 6.80, P = .03), time to extubation (8.7 ± 6.95 vs 10.31 ± 8.69 hours, P = .03), first 12 hours mediastinal drainage in ICU (611.9 ± 341.4 vs 922.2 ± 145.6 mL, P = .03), and ICU stay (1.6 ± 0.58 vs 2.9 ± 1.37 days, P = .001) were significantly less in the off-pump group when compared to the on-pump group, and saturation at discharge (99.7 ± 0.60 vs 98.6 ± 2.13, P = .026) was higher in the off-pump group. However, the average daily pleural drainage (125 ± 61.72 vs 150 ± 103.4 mL, P = .7), time to removal of chest tubes (12.69 ± 7.1 vs 15.44 ± 19.26 days, P = .45), and the total hospital stay (14.23 ± 7.4 vs 18.89 ± 19.9 days, P = .22) were no different. There were substantial savings in costs in patients undergoing off-pump TCPC (P = .016).

CONCLUSIONS

The TCPC without CPB is easy to perform, is cost-effective, and is associated with superior early postoperative outcomes as compared to TCPC on CPB. With appropriate modifications, this operation can be performed in almost all morphological subsets of patients who do not need an associated intracardiac procedure.

Patient-specific assessment of cardiovascular function by combination of clinical data and computational model with applications to patients undergoing Fontan operation

The assessment of cardiovascular function is becoming increasingly important for the care of patients with single-ventricle defects. However, most measurement methods available in the clinical setting cannot provide a separate measure of cardiac function and loading conditions. In the present study, a numerical method has been proposed to compensate for the limitations of clinical measurements. The main idea was to estimate the parameters of a cardiovascular model by fitting model simulations to patient-specific clinical data via parameter optimization. Several strategies have been taken to establish a well-posed parameter optimization problem, including clinical data-matched model development, parameter selection based on an extensive sensitivity analysis, and proper choice of parameter optimization algorithm. The numerical experiments confirmed the ability of the proposed parameter optimization method to uniquely determine the model parameters given an arbitrary set of clinical data. The method was further tested in four patients undergoing the Fontan operation. Obtained results revealed a prevalence of ventricular abnormalities in the patient cohort and at the same time demonstrated the presence of marked inter-patient differences and preoperative to postoperative changes in cardiovascular function. Because the method allows a quick assessment and makes use of clinical data available in clinical practice, its clinical application is promising.

The clinical outcomes of damus-kaye-stansel procedure according to surgical technique

Background

The Damus-Kaye-Stansel (DKS) procedure is a method for mitigating the risk of systemic ventricular outflow tract obstruction (SVOTO). However, there have been few reports on which surgical technique shows a better outcome. The objective of this study was to compare the outcome of the DKS procedure according to the surgical technique used.

Methods

We retrospectively reviewed 12 consecutive patients who underwent the DKS procedure from March 2004 to April 2013. When the relationship of the great arteries was anterior-posterior, the double-barrel technique (group A) was performed. If the relationship was side-by-side, the ascending aortic flap technique (group B) was performed.

Results

There was no early mortality and 1 late mortality in group B. There was no statistically significant difference in the median peak pressure gradient of preoperative subaortic stenosis in both groups: 14 mmHg (range, 4 to 53 mmHg) in group A and 15 mmHg (range, 0 to 30 mmHg) in group B (p=0.526). Further, a significant postoperative pressure gradient was not observed in either group A or group B. More than moderate postoperative neoaortic regurgitation was observed in 1 patient of group B; this patient underwent neoaortic valve replacement 66 months after the DKS procedure. No one had a recurrent SVOTO during follow-up.

Conclusion

The DKS procedure is an effective way to minimize the risk of SVOTO, and there is little difference in the outcomes of the DKS procedure according to the surgical technique used.

Favourable mid-term outcome after heart transplantation for late Fontan failure

OBJECTIVES

Fontan failure (FF) represents a growing and challenging indication for paediatric orthotopic heart transplantation (OHT). The aim of this study was to identify predictors of the best mid-term outcome in OHT after FF.

METHODS

Twenty-year multi-institutional retrospective analysis on OHT for FF.

RESULTS

Between 1991 and 2011, 61 patients, mean age 15.0 ± 9.7 years, underwent OHT for failing atriopulmonary connection (17 patients = 27.8%) or total cavopulmonary connection (44 patients = 72.2%). Modality of FF included arrhythmia (14.8%), complex obstructions in the Fontan circuit (16.4%), protein-losing enteropathy (PLE) (22.9%), impaired ventricular function (31.1%) or a combination of the above (14.8%). The mean time interval between Fontan completion and OHT was 10.7 ± 6.6 years. Early FF occurred in 18%, requiring OHT 0.8 ± 0.5 years after Fontan. The hospital mortality rate was 18.3%, mainly secondary to infection (36.4%) and graft failure (27.3%). The mean follow-up was 66.8 ± 54.2 months. The overall Kaplan-Meier survival estimate was 81.9 ± 1.8% at 1 year, 73 ± 2.7% at 5 years and 56.8 ± 4.3% at 10 years. The Kaplan-Meier 5-year survival estimate was 82.3 ± 5.9% in late FF and 32.7 ± 15.0% in early FF (P = 0.0007). Late FF with poor ventricular function exhibited a 91.5 ± 5.8% 5-year OHT survival. PLE was cured in 77.7% of hospital survivors, but the 5-year Kaplan-Meier survival estimate in PLE was 46.3 ± 14.4 vs 84.3 ± 5.5% in non-PLE (P = 0.0147). Cox proportional hazards identified early FF (P = 0.0005), complex Fontan pathway obstruction (P = 0.0043) and PLE (P = 0.0033) as independent predictors of 5-year mortality.

CONCLUSIONS

OHT is an excellent surgical option for late FF with impaired ventricular function. Protein dispersion improves with OHT, but PLE negatively affects the mid-term OHT outcome, mainly for early infective complications.

Pulmonary arteriovenous malformations after the superior cavopulmonary shunt: mechanisms and clinical implications

Children with functional single ventricle heart disease are commonly palliated down a staged clinical pathway toward a Fontan completion procedure (total cavopulmonary connection). The Fontan physiology is fraught with long-term complications associated with lower body systemic venous hypertension, eventually resulting in significant morbidity and mortality. The bidirectional Glenn shunt or superior cavopulmonary connection (SCPC) is commonly the transitional stage in single ventricle surgical management and provides excellent palliation. Some studies have demonstrated lower morbidity and mortality with the SCPC when compared with the Fontan. Unfortunately the durability of the SCPC is significantly limited by the development of pulmonary arteriovenous malformations (PAVMs) which have been commonly attributed to the absence of hepatic venous blood flow and the lack of pulsatile flow to the affected lungs. Abnormal angiogenesis has been suggested as a final common pathway to PAVM development. Understanding these fundamental mechanisms through the investigation of angiogenic pathways associated with the pathogenesis of PAVMs would help to develop medical therapies that could prevent or reverse this complication following SCPC. Such therapies could improve the longevity of the SCPC, potentially eliminate or significantly postpone the Fontan completion with its associated complications, and improve long-term survival in children with single ventricle disease.

Fontan operation for the Cantrell syndrome using a clamshell incision

A median sternotomy could be difficult for a child with ectopia cordis and complex congenital cardiac anomalies. We report a patient with ectopia cordis, functionally single ventricle and bilateral superior vena cava, who underwent a staged Fontan procedure through a clamshell incision and the sternothoracotomy approach.

Resistance training improves cardiac output, exercise capacity and tolerance to positive airway pressure in Fontan physiology

BACKGROUND

Subjects with Fontan-type circulation have no sub-pulmonary ventricle and thus depend exquisitely on the respiratory bellows and peripheral muscle pump for cardiac filling. We hypothesised that resistance training to augment the peripheral muscle pump might improve cardiac filling, reduce inspiratory-dependence of IVC return to the heart and thus improve exercise capacity and cardiac output on constant positive airway pressure (CPAP).

METHODS

Eleven Fontan subjects (32+/-2 years, mean+/-SEM) had cardiac magnetic resonance imaging (MRI) and exercise testing (CPET); six underwent 20 weeks of high-intensity resistance training; others were non-exercising controls. After training, CPET was repeated. Four trainers had MRI with real-time flow measurement at rest, exercise and on CPAP in the trained state and following a 12-month detrain.

RESULTS

In the trained state, muscle strength increased by 43% (p=0.002), as did total muscle mass (by 1.94 kg, p=0.003) and peak VO2 (by 183 ml/min, p=0.02). After detraining, calf muscle mass and peak workload had fallen significantly (p<0.03 for both) as did peak VO2 (2.72 vs. 2.18 l/min, p<0.001) and oxygen pulse, a surrogate for SV (16% lower, p=0.005). Furthermore after detraining, SV on MRI decreased at rest (by 11 ml, p=0.01) and during moderate-intensity exercise (by 16 ml, p=0.04); inspiratory-dependent IVC blood return during exercise was 40% higher (p=0.02). On CPAP, cardiac output was lower in the detrained state (101 vs. 77 ml/s, p=0.03).

CONCLUSIONS

Resistance muscle training improves muscle mass, strength and is associated with improved cardiac filling, stroke volume, exercise capacity and cardiac output on CPAP, in adults with Fontan-type circulation.

Usefulness of the Guglielmi detachable coil for embolization of a systemic venous collateral after Fontan operation: A case report

Embolization of collateral veins is often treated with rigid coils (Gianturco and interlocking detachable coils type). However, when dealing with tortuous and dilated collateral veins, there is a high risk for technical failure and coil migration due to inflexibility of the coils. To safely and successfully solve this problem, Guglielmi detachable coils (GDC) can be used for embolization. Their flexibility allows for easy navigation in tortuous veins, low risk of unintended coil release or coil migration, and safe deployment. A 12-year-old girl with a single ventricle had severe cyanosis and a low exercise tolerance 5 years after Fontan procedure. The symptoms were caused by a tortuous and dilated collateral from the left phrenic vein into the left pulmonary vein, forming a right-to-left shunt. The collateral, which had a large diameter and high flow, and therefore a high risk of coil migration, was successfully embolized with 8 GDC. There were no complications such as coil migration or cerebral infarction. Transcatheter embolization increased her systemic oxygen saturation from 81%-84% to 94%-95%, and increased her ability to exercise. The embolization procedure using flexible GDC was low risk compared with other rigid coil embolization techniques when performing embolization of tortuous and dilated collateral veins.

Ventricular septation for double inlet left ventricle

Ventricular septation is a biventricular repair for certain types of functionally univentricular hearts. Double inlet left ventricle (DILV) is one type of functionally univentricular heart which in certain instances is amenable to ventricular septation. Thirty-four patients underwent ventricular septation for DILV from 1971 to 2000. Hospital death occurred in seven and late death in two. Mean follow-up period was 15 years. Actuarial survival rate was 73.3% (24 patients) at 15 years, 73.3% (15 patients) at 20 years, 73.3% (five patients) at 25 years, and 73.3% (one patient) at 30 to 40 years. Ventricular septation is an alternative to Fontan operation for selected patients with single ventricle, DILV.

Acute ischemic stroke in a child with cyanotic congenital heart disease due to non-compliance of anticoagulation

BACKGROUND

Stroke is a common presentation in geriatric patients in emergency department but rarely seen in pediatric patients. In case of acute ischemic stroke in pediatric age group, management is different from that of adult ischemic stroke where thrombolysis is a good op.

METHODS

We report a case of a 17-year-old male child presenting in emergency with an episode of acute ischemic stroke causing left hemiparesis with left facial weakness and asymmetry. The patient suffered from cyanotic congenital heart disease for which he had undergone Fontan operation previously. He had a history of missing his daily dose of warfarin for last 3 days prior to the stroke.

RESULTS

The patient recovered from acute ischemic stroke without being thrombolyzed.

CONCLUSION

In pediatric patients, acute ischemic stroke usually is evolving and may not require thrombolysis.

Evaluation of exercise capacity with cardiopulmonary exercise testing and BNP levels in adult patients with single or systemic right ventricles

INTRODUCTION

The aim of the study was to evaluate exercise capacity using cardiopulmonary exercise test (CpET) and serum B-type natriuretic peptide (BNP) levels in patients with single or systemic right ventricles.

MATERIAL AND METHODS

The study group included 40 patients (16 males) - 17 with transposition of the great arteries after Senning operation, 13 with corrected transposition of the great arteries and 10 with single ventricle after Fontan operation, aged 19-55 years (mean 28.8 ±9.5 years). The control group included 22 healthy individuals (10 males) aged 23-49 years (mean 30.6 ±6.1 years).

RESULTS

The majority of patients reported good exercise tolerance - accordingly 27 were classified in NYHA class I (67.5%), 12 (30%) in class II, and only 1 (0.5%) in class III. Cardiopulmonary exercise test revealed significantly lower exercise capacity in study patients than in control subjects. In the study vs. control group VO(2max) was 21.7 ±5.9 vs. 34.2 ±7.4 ml/kg/min (p = 0.00001), maximum heart rate at peak exercise (HRmax) 152.5 ±32.3 vs. 187.2 ±15.6 bpm (p = 0.00001), VE/VCO(2) slope 34.8 ±7.1 vs. 25.7 ±3.2 (p = 0.00001), forced vital capacity (FVC) 3.7 ±0.9l vs. 4.6 ±0.3 (p = 0.03), forced expiratory volume in 1 s (FEV(1)) 3.0 ±0.7 vs. 3.7 ±0.9l (p = 0.0002) respectively. Serum BNP concentrations were higher in study patients than in control subjects; 71.8 ±74.4 vs. 10.7 ±8.1 (pg/ml) respectively (p = 0.00001). No significant correlations between BNP levels and CpET parameters were found.

CONCLUSIONS

Patients with a morphological right ventricle serving the systemic circulation and those with common ventricle physiology after Fontan operation show markedly reduced exercise capacity. They are also characterized by higher serum BNP concentrations, which do not however correlate with CpET parameters.